Abstracts
Evaluation of Dynamic Fracture Characteristics of
By Staton, John
Michigan Department of Transportation
425 W Ottawa St
Lansing, MI 48909
PH: 517-373-2090
FAX: N/A
E-Mail: STATONJ@mdot.state.mi.us
Problem Statement
This project is intended to characterize coarse aggregate used in concrete pavement in terms of its resistance to fracture from dynamic loading. Gravel, crushed rock/stone, and blast-furnace slag are represented in the study. Samples of the aggregate were obtained from active sources that are likely providers of coarse aggregate. Sources throughout Michigan, Ontario and northern Ohio were utilized. The project includes an extensive literature search and review of similar research.
Research Objectives
Primary tasks of the project are: Determine the aggregate's dynamic strength and toughness from uniaxial compression testing within a range of likely loading rates encountered in the field. This work includes an evaluation of how the aggregate's microstructure contributes to the result. Determine the split-tensile strength of concrete cast with each aggregate. Correlate these results with the dynamic testing results.
Research Method
Conduct shear testing of cast concrete prisms using each aggregate to measure (quantify) the relative affects of aggregate interlock across the crack face. Each aggregate type provides a different benefit to resist dynamic (shear) loading as a vehicle axle crosses a crack or joint in a pavement slab.
Product
Provide an assessment of laboratory testing, as it could apply to revising specifications for selecting coarse aggregate for concrete pavement. If successful, the revised specifications would identify minimum physical/mechanical requirements of the coarse aggregate particles to provide minimum load transfer efficiencies across joints or transverse cracks, if they should occur during the pavement's service life.
Completion Date: Dec 31, 2002
Category: Materials
Keywords: aggregates, dynamic fracture, jointed concrete, pavement, PCC Pavements, reinforced concrete,
Date Posted: Nov 13, 2001
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